1. Technical Field
The present disclosure relates to a semiconductor device.
2. Description of Related Art
In recently, the technologies of Si-based semiconductor are developed and have been mature. However, as the sizes of the semiconductor devices become smaller, it brings out some bottlenecks about the device characteristics come from the semiconductor material thereof. Many new technologies of other semiconductor device to replace Si-based semiconductor are therefore presented. The III-V group semiconductor, especially the nitride-based semiconductor material, gallium nitride for example, possesses special spontaneous polarization, high electron saturation velocity, and high breakdown electric field. Since the generation of two dimensional electron gas (2DEG) is caused by spontaneous polarization, the nitride-based semiconductor is received more attentions in the art, especially it can be applied to a normally-off transistor.
The electrical parameters of transistors, such as breakdown voltage, threshold voltage, or switch resistance, need to be tuned in varies ways to satisfy the requirements of different products. However, the adjustments among parameters are usually repelled to each other. For example, one parameter may be deterioration while another parameter is optimized. Thus, an equivalent circuit integrated of plural circuit devices is provided to avoid this situation. However, it still faces some difficulties about how to integrate the nitride-based semiconductor devices since the technologies of the nitride-based semiconductor are not so mature as that of the Si-based semiconductor.